Reigning U.S. Women's Amateur champion Kimberly Kim finished second, one stroke back, after another 69 on the 6,094-yard, par-72 Kearney Hill Golf Links.
'I think it's an honor to be medalist,' said Lua, competing in her seventh USGA championship. '(But) tomorrow, everything is gone. I am pretty much starting over all over again. Tomorrow is when the real fun begins.'
Korean Wonjoo Choi had a 71 and left-hander and Marci Turner, of Tompkinsville, Ky., shot 70 to tie for third at 141.
The 64-player match-play cut came at 9-over 153, with eight players scheduled to return Wednesday morning at 7:30 a.m. to play for the final five spots into the 64-player match-play draw. First-round matches will be played Wednesday, with the 36-hole final scheduled for Saturday.
The oldest to make match play was the Philippines' Ana Imelda Tanpinco, who turns 24 on Sunday; the youngest was 12-year-old Annie Park of Levittown, N.Y. Korean-born Julie Yang, 11, of Phoenix, the youngest in the field, missed by one stroke.
Play was suspended twice for a total of 122 minutes in the afternoon due to thunderstorms.
Lua struggled with her driver most of the day, hitting only six of 14 fairways. She did have a pair of three-putts at holes 7 and 17. She closed her round by hitting a wedge approach to the 459-yard, par-5 18th hole within six feet of the flag and making the birdie putt.
Her other birdies came at holes 3 (3-footer), 5 (5-footer), 13 (25-footer) and 16 (2-footer).
'Today I was trying to fix (my driver) on the back nine and I did for a few holes, so that was good,' said Lua. 'If you hit the fairways here, it gives you chances to get close. I was just a little quick on the backswing (with the driver) and it throws off my timing.'
Kim believed the pressure of being the reigning Women's Amateur champion raised other people's expectations of her.
'Yeah because people just expect me to do good and I don't think they should,' said Kim. 'It makes me feel not so great because people expect something.
'I just want to play more consistently. If I lose my first match and I know I played well, then that's fine.'
The Women's Amateur Public Links is one of 13 national championships conducted by the USGA, 10 of which are strictly for amateurs.
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